package guava;

import com.google.common.base.Optional;

/**
 * Test
 *
 * @author nanxin.chen
 * @date 2015/9/6
 */
public class Test {
    public static void main(String[] args) {
        Optional a = Optional.fromNullable(null);
        Optional b = Optional.of(new Integer(12));
//        Preconditions.checkState();
    }
}
